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(No Model.) 4 Sheets-Sheet 1. A. GRAHAM. ELEOTRIG ARC LAMP.

No. 268,218. Patented Nov. 28, 1882.

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ELEGTRIG ARC LAMP.

.No. 268,218. Patented Nov. 28. 1882.

(No Model.) 4 Sheets-Sheet 4. A. GRAHAM.

ELECTRIC ARC LAMP.

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PATENT OFFICE,

ALFRED GRAHAM, OF LONDON, ENGLAND.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 268,218, dated November28, 1882. Application filed July 18, 1882. (No model.) Patented inEngland March 10,1882, No. 1,171.

To all whom it may concern Be it known that I, ALFRED GRAHAM, of London,England, have invented new and useful Improvements in Mechanism forRegulating the Burning of Carbon 01' other Electrodes in ElectricLightingApparatus and for Similar Purposes, (for which l have obtained apatent in Great Britain, No. 1,171, hearing date March 10, 1882,) ofwhich the following is a specification, reference being bad to theaccompanying drawings.

This invention relates to mechanism chiefly designed to be applied toelectric lamps or lighting apparatus for regulating the burning of thecarbon or other electrodes thereof, and maintaining the arc at itsnormal length; but the said mechanism may also be employed for similarpurposes.

Various contrivances have been adopted by inventors and manufacturers ofelectric lighting apparatus to obviate the inconvenience arising fromirregularity in the burning of the carbons or electrodes, thisirregularity being in some lamps sutiiciently conspicuous to materiallyimpair the lighting effect, and to counterbalance the advantages arisingfrom the brilliancy and other properties of the electric light. Some ofthese contrivances have been found to serve the desired purpose to someextent-that is to say, they reduce the unsteadiness or jumping of thelight; but none of them have proved quite satisfactory, and some of themare so complicated in their construction as to render their maintenancein proper working condition a matter of grea difficulty.

Now, my invention is chiefly designed to afford means for obtaining thedesired resultthat is to say, insuring a practically-perfect regularityor uniformity of the light by the use of mechanism or apparatus which issimple in its construction and not easily liable to derangement.

In the accompanying drawings, Figure 1 represents a vertical sectionalelevation of an electric lighting apparatus to which one form of myimproved regulating mechanism is applied. Fig. 2 represents a frontelevation of part of the same with the front of the casing removed.F.igs. 3 and 4 show detached views of this form of regulating mechanismdrawn to an enlarged scale. Fi 5 shows a moditication in which thecarbons are belowthe regulating mechanism. Fig. 6 represents a verticalsectional elevation of an electric lighting apparatus in which thecarbons come together at an angle or in the form of a V, and having theimproved regulating mechanism applied thereto. Fig. 7 represents part ofthe said mechanism detached.

Oneformormodificationol'myimproved regulating mechanism is constructedas follows thatis to say, I arrangein combination with the electrodesand their holders an escapement device, such as that known as the crown,vergejor Dutch-clock escapement,f0rcontrolling the rotation of a wheelover which passes a chain or cord whose opposite ends are connected tothe holders of the two electrodes, the said wheel allowing the chain orcord to pass over it at a slow and uniform rate, governed by the actionof the escapement, which,by means of the devices hereinafter described,is alternately stopped and released in such a manner as to actautomatically for regulating the burning of the carbons or electrodesand maintaining the are at its normal length.

In Figs. 1 and 2, A A are the carbons or electrodes, held in sockets BB. The socket B is fixed to the top of a metal rod, 0, which extends tothe bottom of the guide-tube D. This guide-tube is provided with a longslot, D, Fig. 2, in which the projecting arm E, fixed to the rod 0, isfree to slide. Attached to the side of the guide-tube D a piece of softiron, F, acting as an armature and placed opposite to the pole of theelectro-magnet G; or I may use a piece of iron rod acting as a corewithin a solenoid. The guide-tube D is arranged to move up and down, andthis up-and-down movement is limited by means of an adjusting device, H.Fixed to and projecting from the guide-tube 1) is a pin or knife, D

K is an. escapement known as the crown, verge, or Dutch-clockescapement, an enlarged view of which is shown in Figs. 3 and 4, and tothe arbor of the escape-wheel or crownwheel L is attached a chain wheelor drum,M, over which is passed a chain or cord, N. One end of the chainor cord N is fast-med to the lower end of the top carbon-holder, O, andthe said chain or cord passes thence over a guide pulley or pulleys, P,to the chain-wheel M, which is provided with pins on its periphery toengage with the links of the chain or to the cord-drum, in which casethe cord is wound several times round the said drum. From thechain-wheel M the chain N extends over an insulated pulley, 1?, carriedby a pin or projection upon the guide-tube D, and is secured to the armE.

The guide-tube D is preferably supported by two spiral springs, Q, Q;but in place of this arrangement the armature or core may be attached toa pivoted lever, one end of which is connected to aspring which tends toseparate the armature from the magnet, the other end of the said leverbeing forked and arranged to support the said guide-tube. In this casethe pin or knife D is carried by that end of the armature-lever which isconnected with the spring.

The pin or knife D projects toward a pin, or by preference a series ofpins forming a comb, R, carried by the cross-arm S of the verge orescapement-arbor S, and these pins are so arranged that when the magnetovercomes the resistance of the spring or springs the pin or knife D ismoved into the path of the pin or one of the pins of the comb R, andthereby arrests the movement of the chain-wheel M.

The current is by preference caused to enter the lamp or lightingapparatus by a terminal, T, insulated from the other parts of theapparatus, then to pass through the coils of the electro-magnet orsolenoid to the bottom carbon-holder, through the bottom carbon to thetop carbon, and thence through the frame to the terminal T. The armatureF being by the passage of the current attracted by the ma gnet G, thesaid armature and the guide-tube D are moved downward, and thus thecarbons are separated, so that the electric arc is formed between them.When the armature is thus attracted by the magnet the pin or knife D ismoved into the path of the pin or comb on the verge or escapement-arbor,as above described, and thus arrests the movement of the crownwheel orescape-wheel L. By using a comb or series of pins the pin or knife D isenabled to arrest the movement of the escape-wheel at any portion of anoscillation of the cross-arm S, instead ofonly atone point in suchoscillation. As the carbons burn away the strength of the current isdiminished, and the electro-magnet becomes gradually weakened until thearmature is pulled ofi' by the action of the spring or springs, and thepin or knife D is thus 'withdrawn from contact with the pin or comb R,thereby releasing the escapcment, which will then act in the followingmanner-that is to say, the weight of the top carbon-holder pulls thechain or cord downward, and the said chain or cord, in passing over thechain-wheel or drum on the crewn-wh eel or escape-wheel arbor, raisesthe bottom carbon rod,the rate of movementof these parts being regulatedor governed by the oscillations of the verge or escapementarbor, so thatthere will be a regular and steady movement of the carbon rods. As thecarbon rods approach each other the strength of the electro-magnet isagain increased, the armature is attracted, and the pin or comb It isagain stopped by the pin or knife-edge D the carbons burn again, and theabove-described actions are repeated until the carbons are consumed.

It will be obvious from the above description that the employment of theaforesaid device, known as the crown, verge, or Dutchclock escapement,is an important feature of my invention, and I adapt this device tovarious forms or modifications of my improved regulating apparatus. Forinstance, I sometimes adopt an arrangement wherein the top carbon-holderis formed with a rack which gears with apinion fixed on the side ofachain wheel or drum, from which a chain or cord extends over the wheelon the crown-wheel or escape-wheel arbor to another wheel, which hasfixed on it a pinion that gears with a rack on the bottom carbon-holder.The downward movement ofthe top carbon and carbon-holder causes themovement of the chain or cord and raises the bottom carbon rod at therate permitted by the escapement,as above described, the two rodsapproaching each other at an equal rate. When it is desired that onecarbon rod or electrode should move more quickly than the other I usepinions of different diameters to gear with the racks on thecarbonholders. The arrangement of the electro-magnet or solenoid and thearmature or core in relation to the escapement is the same as that abovedescribed.

In the apparatus shown in Figs. 1 and 2 the carbons are above theregulating mechanism; but according to another modification of myinvention (illustrated in Fig. 5) I construct a lamp with the carbonsbelow the regulating mechanism. The clectro-magnet or solenoid and thearmature or core are arranged in connection with the escapementsubstantially as in the lamps above described; but their position isreversed. The current from the mav chine or battery enters theelectro-magnet coils or solenoid, and passes thence through onecarbon-holder and carbon, and thence through the other carbon and itsholder to the machine. The armature, when attracted by the magnet, liftswith it the top carbon and places the pin or knife D in the path of thepin or comb R, thereby locking the verge or escapement-arbor. When thecarbons burn away the power of the electro-magnet is diminished, asabove described, and allows the armature to descend and release theverge or escapement-arbor, which then acts, and as the carbons approacheach other the strength of the electro-magnet again increases, thearmature is attracted, the pin or knife D again engages with the pin orcomb R and stops the movement of the carl l i bons, and the operationsare repeated, asabove specified.

In Fig. 6 is shown an arrangement ofa lamp with the carbons comingtogether in the form of a V. The carbons are separated by the armature Fbeing attracted by the electro-magnet Gr, and the pin or knife Dentering the path of one of the series of pins R, stops the movement ofthe drum U until the carbons burn away and an adjustment is required.Two chains or cords are employed in this case, and are both attached byone end to the drum U and by the other to the carbon-holders.

I am aware that in an arc-lamp the carbonholders have been operatedbyseparate chains or cords attached to and wound upon separate drums,the motion of said drums being controlled by a train of gear-wheelsgoverned byan escapement, and I do not claim such a combination ofdevices, broadly.

What I claim isv 1. In an electric-lamp regulating mechanism, thecombinatiomwith the continuous carbon-feedin g chain or cord, havingeach end attached to a movable carbon-holder and passing over suitablepulleys, of a rotary drum having an intermediate portion of said cord orchain in engagement therewith, a stationary escapement arranged tocontrol the motion of said drum, a detent carried by a carbon-holder andarranged to arrest the motion of said escapement, and an eleetro-magnetarranged to move said carbon-holder, substantially as described.

2. The combination, with the stationary escapement, mechanism arrangedto regulate the feed of the carbons, and having the escapement S,provided with a cross-arm carrying a comb, R, of the carbon-holdercarrying the knife D arranged to engage with the teeth of said comb,substantially as described.

3. The combination, with a fixed lower carbon-holder and a movable uppercarbon-holder, having a pin to which the two ends of a chain or cord areattached, the said chain passing over the pulleys P P, and over thechain wheel or drum M, of an escapement device adapted to regulate themovement of the said chain wheel or drum, and having fixed upon itscross-arm a pin or a series of pins forming a comb, and a pin or knifecarried by the guide-tube D, and adapted to be alternatelyengaged withand released from one of the said pins by means of the electro-magnet Gand its armature F and the weight of the upper carbon-holder, allsubstantially as shown and described, and for the purposes specified.

ALFRED GRAHAM.

Witnesses:

GEO. J. B. FRANKLIN, G. W. WEs'rLEY, Both of 17 Gracechurch Street,London, I]. 0.

